<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Insert title here</title>
</head>
<body>
<%!  
 Color getRandColor(int fc,int bc){  
    Random random=new Random();  
    if(fc>255)fc=255;  
    if(bc>255)bc=255;  
    int r=fc+random.nextInt(bc-fc);  
    int g=fc+random.nextInt(bc-fc);  
    int b=fc+random.nextInt(bc-fc);    
    return new Color(r,g,b);  
}  
%>  
<%  
int width=60,height=20;  
BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);  
Graphics g=image.getGraphics();  
Random random=new Random();  
g.setColor(getRandColor(200,250));  
g.fillRect(0,0,width,height);  
g.setFont(new Font("Times New Roman",Font.PLAIN,18));  
g.setColor(getRandColor(160,200));  
for(int i=0;i<155;i++){  
    int x=random.nextInt(width);  
    int y=random.nextInt(height);  
    int x1=random.nextInt(12);  
    int y1=random.nextInt(12);  
    g.drawLine(x,y,x+x1,y+y1);  
}  
//get the random number  
String sRand="";  
for(int i=0;i<4;i++){  
    String rand=String.valueOf(random.nextInt(10));  
    sRand+=rand;  
    g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));  
    g.drawString(rand,13*i+6,16);  
}  
//put the checkNumber into session  
session.setAttribute("verify_code",sRand);  
response.reset(); //如果不加此句，在weblogic下，验证码不显示。  
g.dispose();  
// ImageIO.write(image,"JPEG",response.getOutputStream());   
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(response.getOutputStream());  
encoder.encode(image);   
  
%>  
  
</body>
</html>